Unable to open /Developer/Applications

I recently purchased a second hand iBook G4. It is running Leopard with the developer tools installed. However, I can't run any of the tools because simply trying to navigate to /Developer/Applications causes Finder to hang for a couple of minutes, then crash. Trying to open any of the applications using Spotlight or Terminal causes the same problem, but it's Spotlight or Terminal that is crashing, not Finder. I have tried running 'verify disk' on the disk utility, to check that this isn't caused by a faulty or currupted disk, but it seems to come out OK. Does anyone have any idea what could be the cause of this problem?

Oh yes, one more thing, a side effect of these crashes is that occasionally when Finder goes down it will take a large proportion of the interface with it (ie. the dock or menubar), it won't come back and I'm forced to do a 'control flower power' hard reset.